At present, various electronic devices such as a cellular phone, a portable music player, a portable computer and a flat-plate computer have been widely used. Generally, these electronic devices comprise a touch sensing unit for receiving inputs of a user so as to facilitate the operation of the user. Movements such as click-on, long-press, dragging, sliding etc. by a user on the touch control zone may bring about corresponding control functions.
In another aspect, a screen lock state has been proposed for present electronic devices for saving power consumption of such devices and avoiding accidental touch thereon by a user at the time when the devices are power on and not being operated. Generally the electronic device may be set to a screen lock state by pressing a button, for example a power button. In the screen lock state, a processing unit (e.g. CPU) of the electronic device may be set to a standby state so that the device does not respond to any touch operation occurred on the touch control zone; a touch screen may also be turned off so that no display or touch detection is performed. When the user wishes to use the electronic device, he or she may remove that lock screen state (hereinafter referred to as “unlock”) so that the electronic device will switch back to the normal operating state.
Among many current electronic devices (such as a smart phone, flat-plate computer), to perform an unlock operation, a user needs to press a certain physical button (such as power switch) to turn on the touch screen while drawing a specified pattern in a specified trace on the touch screen to unlock. Such operation is considered to be complicated. Generally, the physical button and the touch screen are set at different outer surfaces of an electronic device and as a result, a user has to operate separately at two different surfaces to unlock, i.e. breaking one operation into two sub-operations. In this case, the electronic device is likely to fall if a user is performing such operations with one hand only.
Furthermore, for example, when the electronic device is in the sleep state, the display unit and touch sensing unit thereof are usually turned off to save battery. For electronic devices without a charging indicator light, when a user wishes to check the progress of charging, he or she may need to take the device and press the physical button (such as power switch) to turn on the display unit in order to check the progress of charging. Similarly, for electronic devices still without a charging indicator light, when such devices are in the power-off and charging state, when a user wishes to check the progress of charge, he or she may need to take the device and press the physical button (such as power switch) to turn on the device and check the progress of charging.